/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation 
 * 
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 * 
 * SPDX-License-Identifier: MIT
 **************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** ThreadX Component                                                     */
/**                                                                       */
/**   Initialize                                                          */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

    extern __tx_initialize_unused_memory

    section .text:CODE:ROOT

/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _tx_initialize_low_level                             RXv2/IAR       */
/*                                                           6.1.10       */
/*  AUTHOR                                                                */
/*                                                                        */
/*    William E. Lamie, Microsoft Corporation                             */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function is responsible for any low-level processor            */
/*    initialization, including setting up interrupt vectors, setting     */
/*    up a periodic timer interrupt source, saving the system stack       */
/*    pointer for use in ISR processing later, and finding the first      */
/*    available RAM memory address for tx_application_define.             */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    None                                                                */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    None                                                                */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    None                                                                */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    _tx_initialize_kernel_enter           ThreadX entry function        */
/*                                                                        */
/*  RELEASE HISTORY                                                       */
/*                                                                        */
/*    DATE              NAME                      DESCRIPTION             */
/*                                                                        */
/*  01-31-2022     William E. Lamie         Initial Version 6.1.10        */
/*                                                                        */
/**************************************************************************/
    public __tx_initialize_low_level

__tx_initialize_low_level:

    /* Save the first available memory address.  */
    // _tx_initialize_unused_memory =  (VOID_PTR) &free_mem_start;

    MOV.L    #__tx_free_memory_start, R1        // Pick up unused memory address
    MOV.L    #__tx_initialize_unused_memory,R2                
    MOV.L    R1,[R2]                            // Save first free memory address

    /* Set priority of SWINT to 1. */
    MOV.L    #0x87303, r1
    MOV.L    #1, r2
    MOV.B    r2, [r1]

    /* Enable SWINT. */
    MOV.L    #0x87203, r1
    MOV.B    [r1], r2
    OR       #(1 << 3), r2
    MOV.B    r2, [r1]

    /* Enable SWINT2. */
    OR       #(1 << 2), r2
    MOV.B    r2, [r1]
    
    RTS

    section FREEMEM:DATA
    public __tx_free_memory_start
__tx_free_memory_start
    DS32    4

    END
